CN110500112A - Earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel to overlap construction method - Google Patents

Abstract

Construction method is overlapped the invention discloses a kind of earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel, it is related to shield field, mainly includes that dewatering design and construction, big cross section Mined, light section shallow buried covered excavation rapid construction technology, the parallel section control technology of shield-tunneling construction and shield-tunneling construction overlap a section control technology.Weaken underground water to banket, the reduction of silt clay, proluvial/slide rock clay, effectively ensured parallel overlap section construction go on smoothly.

Description

Earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel to overlap construction method

Technical field

Construction method is overlapped the present invention relates to a kind of earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel, relates generally to shield Structure field.

Background technique

The analysis influenced by engineering geology, hydrogeology, geotechnical engineering and environment, it is known that overlap section construction parallel and exist Very more engineering problems will lead to engineering accident if cannot reasonably handle the above problem in construction period Generation.Main heavy difficult point risk is as follows:

1) loosely, homogenieity is poor for earthfill structure, is also easy to produce collapsing, part construction is across thicker section of banketing；

2) siltstone, argillaceous siltstoue layer self are poor, under underground engineering construction perturbation action, are easy to make powder Particle loss occurs under the action of water for sandstone, causes Stratum Loss, excavation face is easy to happen collapsing；

3) mud stone, silty mud rock stratum surrounding rock stability and globality are preferable, but country rock air-dries easy to crack, then absorbs water and easily collapses Solution, and there is strong dilatancy；

4) during grouting at the tail of the shield machine, if grouting pressure, injection slurry proportion are uncomfortable, easily cause ground settlement or protuberance；

5) there are mud stone, shield to be easy to form mud cake on cutterhead, make on face in driving on stratum within the scope of tunnel Appearance loses knife, and the situation of mud mill soil causes drilling depth slow；

6) when the surface collapse caused by shield is with swelling excessive, increase existing building composition deformation nearby or sedimentation, Influence its safety and normal use；For underground pipe network, bending will be generated because of stratum deformation and will be destroyed；

7) alternating layers stratum causes face positive pressure uneven, influences the control of shield axis.

Summary of the invention

For the above the deficiencies in the prior art, the present invention proposes that a kind of earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel Overlap construction method, weaken underground water to banket, the reduction of silt clay, proluvial/slide rock clay, effectively ensured parallel Overlap going on smoothly for section construction.

In order to achieve the above objectives, the technical scheme is that including dewatering design and construction, big cross section boring construction skill Art, light section shallow buried covered excavation rapid construction technology, the parallel section control technology of shield-tunneling construction and shield-tunneling construction overlap a section control technology.

It technical principle of the invention and has the beneficial effect that:

Weaken underground water to banket, the reduction of silt clay, proluvial/slide rock clay, reduce have expansile mud stone Breathing destroy, prevent rich water sandstone from destroying water burst, such as banket to weak soil, silt clay, proluvial/slide rock clay carry out it is pre- It reinforces, lower main track and enters and leaves influencing each other for section line parallel section, increase the excavation stability in weak surrounding rock, it is effective to protect Hinder and has overlapped going on smoothly for section construction parallel.

Further, the dewatering design and construction as follows include core pipe production prepare, drilling machine march into the arena, location and installation, aperture, Punching changes slurry, downhole pipe, dilutes mud, fill out filtrate, sealing sealing of hole, well-flushing, lower pump examination pumping, close behind lower mouth guard tube, drilling, whole hole Reason arranges discharge pipe line and cable circuit, test, formally draws water and record；

Described to fill out filtrate: mud is diluted to 1.05 or so afterwards in place by well casing, and when diluting mud, well casing nozzle should be sealed, Carry out mud should gradually slowly from ground, dilution mud is returned between ring-type of the filter through well casing and hole wall.Dilute mud ratio Pump amount is turned down after focusing on 1.05, filling 10~20mm gravel packing is at away from aperture 2m.When filling out filtrate, well head is first covered, is adopted Manually uniformly slowly inserted from well casing surrounding, meanwhile, using water filling filler, slow filler.

Further, big cross section Mined is as follows: using three benching tunnelling methods, step uses short step, at the beginning of upper half section Phase supporting includes: advanced tubule, first pneumatically placed concrete, installs anchor pole, hangs steel mesh, vertical grid steel frame, pneumatically placed concrete to design Thickness；

When wall rock geology is poor, excavated surface is unstable, it is staggered using short drilling depth or up/down steps and excavates or reserve Core Soil measure reinforces excavated surface using gunite concrete or glass fibre anchor pole；

Isolation pile is arranged in the range of shield section and bored tunnel clear distance less than 4m, it is ensured that shield safety is excavating Bored tunnel, reduce shield tunnel construction process two tunnel and influence each other.

Further, light section shallow buried covered excavation rapid construction technology includes benching tunnelling method excavation and earth excavation；

Benching tunnelling method includes top bar excavation and support, get out of a predicament or an embarrassing situation excavation and support and inverted arch excavation and support；

Top bar excavation and support sequence of construction: temporary enclosed face (depending on country rock situation), advanced tubule are squeezed into, are surpassed Preceding grouting with small pipe strengthening stratum stays Core Soil to excavate the top bar earthwork, measurement excavated section profile, just spray concrete 40mm, installation Steelframe sets lock foot anchor tube, the longitudinally connected muscle of installation, hangs steel mesh, again spray concrete to design thickness；

Get out of a predicament or an embarrassing situation excavation and support sequence of construction: left side abutment wall earth excavation, measurement excavated section profile, just spray 40mm is thick Concrete installs steelframe, sets anchor pole, hangs steel mesh, again spray concrete to design thickness, right side abutment wall earth excavation, measurement excavated section Profile, just spray 40mm thickness concrete install steelframe, set anchor pole, hang steel mesh, again spray concrete to design thickness；

Inverted arch excavation and support sequence of construction: tunnel bottom earth excavation, measurement excavated section profile, just spray concrete 40mm, installation Shaped steel arch hangs steel mesh, sprays concrete again to design thickness, and excavation length of inverted arch is not greater than 3m, digs to design profile, Steelframe, injection coagulation are installed immediately.

Further, the parallel section control technology of shield-tunneling construction is as follows: isolation pile is applied between bored tunnel and shield section, When the clear distance in bored tunnel and shield section is less than 4m, isolation pile is set between two works, two face bouts In isolation pile cutoff, shield, which could tunnel, to be passed through for position selection, and bored tunnel stops after excavating, and spray anchor closes face, is being appeared on the stage Fashioned iron stull is arranged in rank bottom, and the perpendicular support of stull middle position setting, stull and perpendicular tie distance are identical as steel arch-shelf, weld with steel arch-shelf It connects, gunite concrete between stull, makes top bar closing cyclization, same position should be excavated with inverted arch by getting out of a predicament or an embarrassing situation, and just branch envelope Close cyclization.

Further, it is as follows to overlap section control technology for shield-tunneling construction: at, engineering dewatering processing good including quarrel land reform and slip casting Reason.

Further, quarrel land reform is good as follows: in clay stratum in driving, respectively to cutterhead face, Tu Cang and screw conveyor Inject foam；When water abundant ground and other aquifer water-bearing stratums tunnel, swelling is injected into cutterhead face, native storehouse and in screw conveyor Soil, and increase to injecting bentonite in screw conveyor；When sandstone layer stratum is tunneled, mud is injected into cutterhead face, native storehouse.

Further, engineering dewatering processing is as follows: dewatering well center is isolated away from bored tunnel edge 2.3-2.5m in turn back line Stake setting area, dewatering well are set on the outside of two isolation piles between stake, and along tunnel longitudinal direction, two rows are staggeredly arranged.

Further, injecting treatment includes section line grouting and reinforcing: running tunnel passes through in range and tunnel top bankets Layer carries out ground steel floral tube tunneling boring pre-pouring grout to above-mentioned soil layer and reinforces；The test of craftsmanship injecting grout through steel perforated pipe is carried out before construction, with The applicability of stratum grouting process is examined, and large area carries out mortar depositing construction after test effect reaches design requirement.

Further, injecting treatment includes into a section line grouting and reinforcing: using the retrusive slip casting of ground steel floral tube to Tunnel Passing Stratum carry out compacted and filling and injecting slurry, slip casting pitch of holes 2m × 2m, front two rows is staggeredly arranged.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, embodiment will be described below Needed in attached drawing be briefly described, it should be apparent that, the accompanying drawings in the following description is only of the invention wherein 7 Width without creative efforts, can also obtain according to these attached drawings for those of ordinary skill in the art Obtain other attached drawings.

Fig. 1 is section line dewatering well layout drawing；

Fig. 2 is into a section line dewatering well layout drawing；

Fig. 3 is section line grouting and reinforcing range plane figure；

Fig. 4 is section line grouting and reinforcing skiagraph；

Fig. 5 is section line stratum consolidation sectional view.

Specific embodiment

Below in conjunction with attached drawing, the technical solution in the present invention is clearly and completely described, it is clear that described Embodiment is only presently preferred embodiments of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, this field Those of ordinary skill's every other embodiment obtained without making creative work, belongs to protection of the present invention Range.

Embodiment

1 isolation pile construction

Design is provided with 1200@of φ, 1500 armored concrete isolation pile, length 62.45 between turn back line tunnel and main track tunnel Rice (RCK0+169.55~RCK0+232.00 section), isolation pile and turn back line bored tunnel clear distance are 0.5m, upper and lower stake end it is embedding Gu depth is 6m, isolation pile is completed to construct in advance.

1.1 working procedure

(1) pile position deviation, axis and vertical axis direction are not preferably greater than 50mm, and pile body perpendicularity deviation is not preferably greater than 0.5%.

(2) construction of mud off method can be used in cast-in-situ bored pile, and steel bushing cylinder-wall can be used when necessary；After drilled pile borehole cleaning Bottom dross thickness must be controlled no more than 200mm.

(3) the suitable sectional making of steel reinforcement cage should take measures to prevent from deforming in lifting, transport, installation, and suspension centre, which is preferably set to, to be added Strong stirrup position, when being segmented sinking, the connection for indulging muscle must will pay special attention to welding quality, reinforcement welding connector using welding The length of jointing is 35d and is not less than 500mm, and same section top connection quantity is not more than 50%.

(4) cast-in-situ bored pile should be taken every pile driving construction, and should concrete perfusion for 24 hours after and adjacent studs body concrete reach It, can drilling construction after 70% or more design strength.

(5) when placing of reinforcement cage, save up and down main reinforcement must to being just connected firmly, and it is qualified on inspection after, can continue.

(6) in filling concrete, conduit should be embedded in concrete always, and conduit is forbidden to propose concrete surface；Conduit should be protected It holds Transducers Embedded in Concrete and pours 2~3m of face or less, once mentioning pipe must not exceed 6m, should prevent rising of steel cage.

(7) thickness of concrete cover of stake steel bar stress is 70mm, and thickness deviation is not preferably greater than 20mm.

(8) steel reinforcement cage diameter deviation is not preferably greater than 10mm, and length of reinforcing cage deviation is not preferably greater than 50mm, main reinforcement spacing deviation It is not preferably greater than 10mm, stirrup spacing deviation is not preferably greater than 20mm.

(9) when constructing in fill stratum, layer of sand, to prevent cell wall from unstable phenomenon occur, it should be selected and be closed according to geological conditions The simulated mud of reason, necessary moment increase mud balance, add bentonite.

(10) the suitable integral hoisting of steel reinforcement cage, steel reinforcement cage, which is hung, answers strict guarantee built-in fitting elevation, and steel reinforcement cage enters after slot to pouring Total holding time is not to be exceeded 4 hours when infusing concrete.

(11) cast-in-place concrete pile that construction is completed need to detect pile body integrity using low-strain dynamic measure method, and amount detection is not It is preferably less than the 20% of total amount of pile, and 5 must not be less than；When the pile defect determined according to low-strain dynamic measure method may influence stake When horizontal bearing capacity, the supplement detection detection of Ying Caiyong core drilling method, quantity should not be less than the 2% of total amount of pile, and must not be less than 3.

2 dewatering designs and construction

To reduce water pressure suffered by tunnel vault and side wall, it is ensured that the dry operating environment construction in tunnel, during boring construction Carry out precipitation.Hypsography is larger along the line, and depth to water changes with hypsography, according to well pumping test scheme arrangement precipitation Well.In tunnel two sides, one row longitudinal direction dewatering well is respectively set, dewatering well bore diameter 800mm, well diameter 400mm, t=4mm, precipitation Well depth enters depth 15m under tunnel, and unilateral dewatering well spacing is 10m and 15m, and dewatering well is staggeredly arranged along tunnel two rows.

1) dewatering well working procedure

Preparation (core pipe production)-drilling machine marches into the arena-the lower mouth guard tube-drilling-end hole of location and installation-aperture-after punching change Slurry-downhole pipe-dilution mud-fills out pump examination pumping-reasonable arrangement discharge pipe line and cable circuit-under filtrate-sealing sealing of hole-well-flushing- Test-formally drawing water-records.

2) dewatering well technique

Dewatering well outer diameter is φ 800m, and central suction core pipe is φ 400mm wall thickness 4mm steel pipe, and 500mm opens φ in tube bottom The circular hole of 20mm spacing 200mm × 200mm, staggeredly blossom type is arranged, manages two layers 60 wooden galvanized wire strainers of outer package；In steel pipe Gravel drainage layer is filled between hole wall, filtrate uses diameter for 10~20mm gravel, and below ground 2m is with 20~30mm's of diameter Air-dried clay ball is tamped to ground.

Pore-forming: dewatering well outer diameter is φ 800m, and using the method for Spiral digging machine pore-forming, construction quality and acceptance criteria are enclosed together Fender pile pore-forming technique.

Borehole cleaning changes slurry: after drilling drilling to designed elevation, sundries in cleaning hole, while mud density in hole being gradually adjusted to 1.10, bottom hole sinks silt thickness less than 30cm, without until clod in the mud returned out.

Lower core pipe: after pipe is marched into the arena, being processed by design requirement, wraps up strainer.Well casing is arranged in advance by design well depth Column, combination, absolute altitude strict control is pressed in the bottom of dewatering well when down tube.Well casing should steadily enter hole, and the two-port of every section well casing will look for Flat, there are 45 degree of slope angles in lower end, and welding Shi Erjie well casing should be looked for directly from two directions, and have two people to be symmetrically welded, it is ensured that welding Vertically, complete zero-clearance guarantees weld strength, in order to avoid fall off.

In order to guarantee that well casing is not carried against on the borehole wall and guarantees drainage layer thickness, respectively add one group of righting in drainage core pipe top and the bottom 4 pieces of device, keep filter pipe placed in the middle, guarantees that annular packing gap thickness, filter should scrub clean, filter pore size is uniform and not small In 2cm, 60 mesh filter screens of double-baging outside.Down tube will accurately in place.Naturally it falling, slightly rotation falls on position, it can not strongly depress, in order to avoid Damage filter structure.

Fill out gravel material: mud is diluted to 1.05 or so afterwards in place by well casing, and when diluting mud, well casing nozzle should be sealed, and makes mud Slurry gradually should be carried out slowly from ground, dilution mud is returned between ring-type of the filter through well casing and hole wall.Dilution mud balance exists Pump amount is turned down after 1.05, filling 10~20mm gravel packing is at away from aperture 2m.When filling out filtrate, well head is first covered, using people Work is uniformly slowly inserted from well casing surrounding, and vehicle filtrate is forbidden to pour into from a direction, meanwhile, using water filling filler, filler Slowly it must not quickly should concentrate and topple over, cause well casing periphery local stoppages, disused well can not be formed at well.

Well-flushing: down tube fills out timely well-flushing after filter material layer, causes well-flushing difficult to avoid mud and the solidification of sand gravel material.Well-flushing Using air compressor machine pumping and washing process, i.e., high pressure air flow is injected to steel pipe bottom using air compressor machine, while with sewage pump toward hole outlet The capacity of slurry, air compressor machine is not less than 7m³/ min, pressure are not less than 0.5Mpa, and well-flushing must be washed until water sand removal is net.

Well head closing: to prevent mud and surface waste water from flowing into well outside pipe, below ground 2m 20~30mm of diameter Air-dried clay ball tamp to ground, cement sand plaster sealing.

Dewatering well operation: each well head of Accurate Determining and ground elevation measure static level, arrange pumping equipment, cable properly And drainage pipeline makees trial operation, to guarantee that pumping system is intact.The water released should be discharged into over-the-counter municipal pipeline, in order to avoid extraction Water bleed back on the spot, influence dewatering effect, it is outer that the rainfall ponding in hole should be discharged hole immediately, reduces to the greatest extent in Atmospheric precipitation and hole Ponding infiltrates.

3) key technology brief summary

It must guarantee at least two weeks or more pre- times of pumping before excavating, guarantee that level of ground water is down to tunnel bottom or less 1m.

Pumping out the water come should be discharged into over-the-counter municipal pipeline, in case the water of extraction is bled back.

Filtrate backfill is the core link of precipitation well construction, should be poured slowly into from core pipe surrounding, and filler should slowly, must not be fast Speed, which is concentrated, topples over, and guarantees that the backfill of core pipe surrounding is uniformly closely knit.

The precipitation operation phase, stand-by generator is answered, prevents from powering off and Breakrainfall.

Construction of structures deformation in periphery should be monitored during precipitation.

3 big cross section Mineds

There are mainly of two types for underground water: being respectively perched water and Bedrock Crevice Water.Perched water is located at artificial along the line It bankets in slide rock viscous soil horizon, water penetration, watery are weak, because the difference of filler and compaction is very uneven.Mainly by Atmospheric precipitation supply, excretion are mainly atmospheric evaporation；Water level, water, the buried depth of perched water are influenced by nourishment condition, variation compared with Greatly, 0.6~12.0m of fixed level buried depth, depth to water absolute altitude are 79.05~93.13m.The main preservation of Bedrock Crevice Water is under 7. volt third system half diagenesis argillaceous siltstoue, siltstone in the crack of layer 2-3, have pressure-bearing property, watery is poor, belong to aquiclude. Fixed level 2.5~12.3m of buried depth, depth to water absolute altitude are 74.25~92.28m.Bedrock Crevice Water Source Of Supply mainly from Supply is infiltrated in Atmospheric precipitation, is drained along water-bearing layer seepage flow.

Excavation method design uses CRD method, but can be adjusted according to practical country rock situation, into hole after revealed country rock Self-stable ability is preferable, and underground water content is seldom, therefore is adjusted to three benching tunnelling methods.

Plan is raised according to work, shield section and bored tunnel inevitably parallel construction, to ensure shield safety The bored tunnel excavated reduces influencing each other for two tunnel of shield tunnel construction process, while isolation pile also serves as tunneling tunnel Road just props up anchor rod anchored end, and in shield section and bored tunnel clear distance, isolation pile, stake diameter 1200mm, stake is arranged in the range less than 4m Spacing 1500mm is embedded in tunnel bottom depth 6m.

3.1 working procedure techniques

Top bar is excavated, and cyclic advance 0.5m can reduce cyclic advance when country rock is poor.

Upper half section preliminary bracing, comprising: advanced tubule, first pneumatically placed concrete install anchor pole, hang steel mesh, vertical grid Steelframe, pneumatically placed concrete to design thickness totally six procedure.

1. advanced tubule: advanced tubule uses A42 hot rolled seamless steel tube, wall thickness 3.5mm, L=3.0m, circumferential spacing 400mm, longitudinal pitch 1500mm are set within the scope of 120 ° of arch, 7~10 ° of outer limb.

2. just spray: use C25 early strength concrete, thick 300mm, arch excavate after the completion of carry out immediately, with closing, it is levelling For the purpose of excavation face prevents sur-face peeling from collapsing, thickness 40mm is just sprayed.

3. installing anchor pole: abutment wall sets C22 grouting rock bolt (or A42 mortar anchor tube wall thickness 3.5mm), L=3.0m, circumferential spacing 1.0 × 1.0m, blossom type arrangement are installed before linked network after first spray, install position and quantity is arranged by design drawing.

4. linked network: steel mesh uses 8 × φ of φ 8,150 × 150mm of grid spacing, this layer of steel mesh installs anchor pole in first spray Later, it is laid with before erecting steelframe.Spraying of reinforcement mat with concrete protective layer thickness is not less than 20mm.

5. vertical grid steel frame: grid steel frame merogenesis is process, and country rock is close to when erecting, and arch springing is arranged in undisturbed formation, And lock foot anchor tube is set, peripherally spacing 1m sets the longitudinally connected muscle of φ 22 between two rows of steelframes, becomes an overall structure, improves Stress.

6. jetting cement wraps up steelframe: using wet shot mode, multiple spray point reaches package steelframe to design thickness several times.

Strict control length of bench, after 3~5m of upper half section excavation drilling depth, excavation is got out of a predicament or an embarrassing situation, every cyclic advance 0.5m, shape Cheng Chuzhi domain closure.It gets out of a predicament or an embarrassing situation and inverted arch preliminary bracing, working procedure, technique is same as above step construction.

3.2 key technology

A. " Guan Chaoqian, tight slip casting, short excavation, strong supporting, fast closing, the diligent measurement of shallow burial hidden digging are followed." 18 words Policy.

B. according to wall rock condition, length of bench and height are rationally determined, when surrounding rock stability is poor, short step should be used, Length of bench is controlled in one times of hole diameter.

C. it when wall rock geology is poor, excavated surface is unstable, is staggered excavation or pre- using short drilling depth or up/down steps Core Soil measure is stayed, excavated surface is reinforced using gunite concrete or glass fibre anchor pole when necessary.

Guarantee the frequency of monitoring measurement, with monitoring measurement guiding construction

The analysis of 3.3 implementation results

Enter in the village a section line turn back line segment bored tunnel on May 1st, 2014 from small mileage end into hole, on August 10th, 2014 From big mileage end into hole, Zhi Guantong at the beginning of on October 31st, 2014 (top bar perforation), branch at the beginning of on November 18th, 2014 is all closed, Excavation average advance is the hole 0.54m/d/, and beginning lining cutting on November 19th, 2014,20 days two March in 2015, lining poured completion (Spring Festival has a holiday or vacation 20 days) it is more normal to excavate progress.

Convergent deformation maximum value is 27.2mm (code requirement≤35mm), and Vault settlement maximum value is that 46.4mm (want by specification Seek≤50mm), ground settlement maximum value is 19.6mm (code requirement≤30mm), is analyzed from monitoring and measurement data, and excavation causes Tunnel deformation it is smaller, all in specification allowed band.

3.4 Summary on technology

A. big cross section shallow-depth-excavation tunnel is high risk engineering, and shield section with bored tunnel is closely parallel applies Work, in order to ensure safety, designing institute uses CRD excavation method, but entering section line in the village is the controlling work that Line 1 head leads to section Journey such as uses CRD method, then can not obviously transfer and lay a railway track on schedule, therefore after multiple research discusses, decision is adjusted to three steps Method, while reinforcing the ancillary measures such as surface grouting, precipitation, isolation pile, and increase temporarily when shield and tunneling face merge It reinforces just branch measure, these measures and has ensured the stabilization of tunnel excavation, opened for Line 1 eastern section and won the valuable duration.

B.CRD method is adjusted to the reasonable application that three benching tunnelling method energy implementation success keys are auxiliary methods, and in auxiliary method Precipitation is particularly critical, and the geologic feature of N-sandstone mud stone is exactly to meet water softening, and then present in anhydrous situation from steady The preferable state of property, reflects clearly, face country rock self-stability is preferable, and is soaked by construction water in practical digging process The inverted arch of bubble then softens seriously.Therefore precipitation is successfully the most basic guarantee that three benching tunnelling methods are smoothly implemented, this engineering can be used as The typical successful case of sandstone mud stone precipitation.

C. by adding isolation pile between shield section and bored tunnel, two constructing tunnels has effectively been blocked to cause Stress transfer, but it was verified that when two tunnel clear distances are less than one times of hole diameter and be greater than 4m when, shield driving to it is existing just branch Molding bored tunnel influence is also very small, and certainly and country rock grade has very big relationship, and shield successfully passes through non-isolated stake area The bored tunnel in domain, this engineering have certain reference value.

4 light section shallow buried covered excavation rapid construction technologies

4.1 benching tunnelling methods excavate

(1) top bar excavation and support

Top bar, which is excavated, uses Ring Cutting remaining core soil in advance, carries out per-fore pouring liquid with small pipe supporting in arch before excavating, Every 0.5~the 1.0m of length of the cycle of Ring Cutting just sprays 40mm thickness concrete after the completion of excavating, then erect shaped steel arch, hangs reinforcing bar Net, gunite concrete to design thickness.

Core Soil should be stayed not less than the 1:1 gradient, and there is not allowed that counter-slope.Top bar excavation height is in 4.4m or so, core Native height 2.5m, Core Soil is apart from wide 2.0m of two sides abutment wall or so, along tunnel piercing direction 3~5m of length, the shape of Core Soil Under the premise of guaranteeing that face is maintained to stablize, as being workbench, in order to carry out steelframe installation, gunite concrete operation It is advisable.

Top bar sequence of construction: temporary enclosed face (depending on country rock situation)-advanced tubule squeezes into-advanced tubule note Slurry strengthening stratum-stays Core Soil to excavate the top bar earthwork-measurement excavated section profile-, and just spray concrete 40mm- installation steelframe-sets lock The longitudinally connected muscle of foot anchor tube-installation-extension steel mesh-sprays concrete to design thickness again.

(2) get out of a predicament or an embarrassing situation excavation and support

3~5m is completed in top bar excavation supporting and top bar preliminary bracing structure is basicly stable, and gunite concrete reaches Design strength 70% or more when carry out excavation of getting out of a predicament or an embarrassing situation, Core Soil is stayed in centre, and Core Soil height 2.0m, Core Soil is apart from two sides Wide 2.0m of abutment wall or so, along tunnel piercing direction 3~5m of length, step excavation.It gets out of a predicament or an embarrassing situation and is opened using the abutment wall unilateral side mode of interlocking It digs, superstructure must not be made hanging simultaneously.The abutment wall of side is first excavated, excavation step pitch is one to two Pin steelframe spacing, is dug extremely After design profile, steelframe is installed immediately, sets anchor pole, m esh-hanging sprayed concrete；It is carried out again after the abutment wall supporting of side another The excavation of side abutment wall and supporting.

It gets out of a predicament or an embarrassing situation sequence of construction: the first spray 40mm thickness concrete-installation steel of left side abutment wall earth excavation-measurement excavated section profile- Frame-sets anchor pole-extension steel mesh-and sprays concrete again to the just spray of design thickness-right side abutment wall earth excavation-measurement excavated section profile- 40mm thickness concrete-installation steelframe-sets anchor pole-extension steel mesh-and sprays concrete again to design thickness

(3) inverted arch excavation and support

According to monitoring result situation, start to carry out inverted arch excavation, supporting closing after excavation supporting of getting out of a predicament or an embarrassing situation completes 5~8m Cyclization construction.

Inverted arch sequence of construction: just spray concrete 40mm- installs shaped steel arch-extension to tunnel bottom earth excavation-measurement excavated section profile- Steel mesh-sprays concrete to design thickness again.Excavation length of inverted arch is not greater than 3m, digs to design profile, installs steel immediately Frame, gunite concrete.

4.1.2 earth excavation and transport

(1) earth excavation

Enter section line double track tunnel and single-track tunnel joint and completes constructing tunnel using 1# vertical shaft.It is enclosed in construction according to tunnel Rock geology and hydrologic condition and surrounding enviroment select reasonable excavation method, and selection principle is less to disturb to surrounding enviroment and country rock It is dynamic, and preliminary bracing and first branch back-grouting are applied in time.It excavates and is tunneled using artificial, pneumatic equipment, mini-excavator, excavated Remaining core soil in advance.The transport of tissue dress quarrel, transport are used flexible transport, are transported to well nest, are promoted using electric block immediately after excavation Systematic vertical is promoted to ground and deposits quarrel Tu Chang, is transported to spoil ground using night concentration is outer.

Strict control drilling depth length follows strictly the principle of " short drilling depth, strong supporting ", the timely anchor of every excavation 0.5m~1.0m It sprays supporting and sets up steel arch-shelf.

(2) the cubic metre of earth and stone is transported outward

Cubic metre of earth and stone outward transport is handled in strict accordance with Nanning urban district quarrel soil outward transport pertinent regulations.It is outer that fortune quarrel vehicle configuration covers quarrel soil Special-purpose vehicle is transported, according to amount of being unearthed the day that Design of Construction Organization is appraised and decided, transports outward the time in conjunction with night, arranges quarrel soil transport dedicated Vehicle plan.Spoir place election has the spoir point of rainy season spoir condition, while firmly obeying owner and wanting to the allotment of the earthwork It asks.According to the requirement of the related civilized construction in Nanning City, fortune quarrel vehicle is driven out to construction site or spoil ground must rinse well after ability Upper road, and be responsible for checking by special messenger and supervise, everyone has responsibility for implementation.In view of the urban district construction infection appearance of the city and increase the pressure of traffic nearby Power, spoir are transported outward and are carried out in time principle in night 22:30-5:30, need to be extended outside time spoir at night if any special circumstances When fortune, related quasi- fortune formality strictly will be handled by regulation.

(3) transportation management

When by inverted arch construction site, to avoid interference of the inverted arch construction to other process, proposed adoption sets up truss frame platform Transition, i.e. vehicle are transitioned by riding upon the truss frame platform of inverted arch construction site and have been poured inverted arch and reach with being open to traffic intensity Section, the bottomed cleaning of inverted arch and casting concrete carry out under the platform, and to the end of inverted arch construction under platform, concrete strength reaches To after the intensity that is open to traffic, mobile platform, so recycles in cycles and promotes further along.

To improve slag discharge efficiency, shortening circulation time guarantees safety, takes following measure:

A, reinforce shipment slag equipment maintenance, prepare enough rapid wear accessory, discovery failure excludes in time.B, it sets special messenger and conserves road Road keeps path formation, without ponding, periodically spreads slag maintenance.Especially rainy season, if special messenger excludes hidden danger in time.C, reinforce Hole internal drainage and illumination keep having good illumination and road conditions in hole.D, reinforce ventilation, guarantee that air is fresh in hole.E, it educates out Slag driver observes traffic rules and regulations, and courtesy driving forbids tape jam to drive a vehicle and drive when intoxicated.F, since intervisibility situation is poor, tunnel In road work progress, signal lamp is installed in hole, allows loaded vehicle principle according to light car, haulage vehicle in hole is organized by full-time dispatcher Traveling, avoid traffic congestion, maintain traffic order.G, Dumping Sites are smooth using bull-dozer, and special messenger commands slag.H, builder's road passes through Often watering, prevents dusty.

The parallel section control technology of 5 shield-tunneling constructions

According to planned management of project, all sorts of flowers ridge station~ridge Fo Zi station shield section must be with bored tunnel synchronous construction, shield pick Into inevitably by the bored tunnel that is excavating, thus tunneling is just propped up when how to prevent shield driving from passing through unstability and How to prevent bored tunnel from transfiniting by the deformation of molded running tunnel section of jurisdiction, is one of this engineering greateset risk.

1) working procedure technique

Isolation pile is applied between bored tunnel and shield section, when bored tunnel and the clear distance in shield section are less than 4m, Isolation pile is set between two works, to separate crustal stress transmitting.

The position of reasonable tunneling pause is selected, in order to reduce the cross influence of tunneling and shield, two faces as far as possible The position of bout should be selected in isolation pile cutoff, i.e., after tunneling face enters isolation pile region, shield, which could tunnel, to be passed through.

Bored tunnel stops after excavating, and spray anchor closes face, and fashioned iron stull, stull interposition is arranged in top bar bottom Perpendicular support is installed, stull and perpendicular tie distance are identical as steel arch-shelf, weld with steel arch-shelf, and gunite concrete between stull makes to appear on the stage Rank closing cyclization.Same position should be excavated with inverted arch by getting out of a predicament or an embarrassing situation, and just branch closing cyclization.

Shield machine slow transits through, and reduces thrust, selects the mode of low speed and large torque, and reinforces the monitoring frequency of bored tunnel Rate.

2) key technology brief summary

A. select tunneling and shield face bout position extremely important, it is necessary to assure in isolation pile region.

B. it is construction guidance with monitoring measurement, increases monitoring frequency, once finding that just branch deformation is abnormal, stops pick immediately Into reinforcing is just propped up.

6 shield-tunneling constructions overlap a section control technology

6.1 quarrel land reforms are good

1) the good method of quarrel land reform

This bid section stratum is mainly silt, silty clay, generates mud cake, water burst in tunneling process in order to prevent, gushes sand, increases The strong native workability that is cut, injects foam in clay tunneling process, injects mud when necessary in powder soil horizon.

2) use of foaming agent

Foam is injected by the foaming system on shield machine.The composition of foam solution: additive foam 3%, water 97%.Bubble Foam composition: 90~95% compressed airs and 5~10% foam solutions mix.The injection rate of foam is calculated by earthwork: Generally 300~600L/m³, shield machine , Pao Droplets dosage when passing through special formation will be adjusted according to the actual situation.

3) use of mud

Shield is contemplated that when promoting in high-moisture stratum, layer of sand injects mud in Tu Cang.

Its match ratio are as follows: water: bentonite: flyash: additive=4:1:1:0.1, adding mud amount is 20%~30% unearthed Amount.Injection pressure is consistent or slightly higher with the support pressure of shield.

Proportion and injection rate are adjusted in time according to geological conditions and condition of construction.

4) the good technical measures of quarrel land reform

In clay stratum in driving, mainly stable excavation face prevents cutterhead from generating mud cake, and reduces cutter head torque. Quasi- to take the method for injecting foam into cutterhead face and native storehouse respectively to carry out quarrel land reform good, can infuse when necessary into screw conveyor Enter foam.

When water abundant ground and other aquifer water-bearing stratums tunnel, mainly to prevent water burst, reduce cutter head torque, intend to cutterhead Bentonite is injected in face, native storehouse and in screw conveyor, and is increased to bentonite is injected in screw conveyor, in favor of spiral transferring It send machine to form soil plug effect, prevents water burst.Bentonite additive amount determines as the case may be.If in usual manner cannot be effective When preventing screw conveyor gate spray quarrel, water burst, pressure maintaining is pumped and is docked on screw conveyor gate by pipeline, soil pressure is established Equilibrium state avoids gushing due to groundwater pressure is excessive in screw conveyor outlet.

It when sandstone layer stratum is tunneled, mainly prevents water burst, gush sand, guarantee that excavation face is stablized, intend to cutterhead face, Tu Cang Interior injection mud increases the native workability that is cut, establishes suitable soil pressure, guarantee the stabilization of excavation face.

The processing of 6.2 engineering dewaterings

Such as Fig. 1 and Fig. 2, enters section line RDK0+169.550~300.000 (130.45m) section dewatering well and go deep into tunnel bottom or less 15m, unilateral dewatering well spacing are 10m, totally 26 mouthfuls of wells；RDK0+300~520 (220m) section dewatering well gos deep into tunnel bottom or less 15m, unilateral dewatering well spacing be 15m, totally 30 mouthfuls；RDK0+520.000~935.878 (415.88m) section dewatering well gos deep into tunnel 13m below bottom, unilateral dewatering well spacing be 15m, totally 55 mouthfuls；CDK0+127.700~540.027 (412.327m) section dewatering well Go deep into tunnel bottom or less 13m, unilateral dewatering well spacing is 15m, totally 54 mouthfuls.

Dewatering well center is away from bored tunnel edge 2.4m, and in turn back line isolation pile setting area, dewatering well is set to two isolation Between stake outside stake, along tunnel longitudinal direction, two rows are staggeredly arranged.Bore diameter 800mm, well casing use φ 325, wall thickness 5mm steel pipe, steel Pipe opening diameter 20mm, 2 layer of 60 mesh braid fabric of outsourcing, drainage layer are not more than the graded broken stone of 20mm using partial size.

Through examining, dewatering well dewatering effect is good, has reached expected purpose.

6.3 injecting treatment

It is shallow to enter and leave section edpth of tunnel, and it is poor to pass through rock stratum, tunnel cave roof fall phenomenon easily occurred by water and driving disturbance, Greatly difficult and security risk is caused to construction, entering and leaving section part route in addition need to complete just before hundred Buddhist main track arrivals Branch construction, to ensure mutual construction safety and construction quality, the slightly mistake normal driving that will affect hundred Buddhist sections, finally Influence the realization of the logical duration node destination in all fronts hole.Therefore, it according to actual formation situation, is carried out entering and leaving section line corresponding site Surface grout injection consolidation process.

1) go out section line grouting and reinforcing

1., this running tunnel passes through in range and the fill stratum of tunnel top, according to geological mapping data evaluation, without place For the fill stratum of reason as tunnel surrounding, stability is very poor, almost without self-stable ability, intends complete to above-mentioned soil layer progress ground steel floral tube Section pre-pouring grout is reinforced；It overlaps overlay segment steel floral tube construction depth and answers strict control, steel floral tube must not invade shield driving model It encloses；Craftsmanship injecting grout through steel perforated pipe test should be carried out before construction, to examine the applicability of stratum grouting process, and reached through test effect It can large area development mortar depositing construction after to design requirement.

2., Grouting Pipe useThe steel pipe of wall thickness t=3.5mm.Grouting Pipe should be goed deep into reinforcing soil layer or less 0.5m. Reinforcing scope is reinforced using cement slurry, slip casting tube spacing 2.0m (being staggeredly arranged).

3., grouting parameter: grouting serous fluid use cement slurry, cement use 42.5 grades of ordinary portland cements, cement slurry Ratio of mud 0.5:1~1:1,1.0~3.0MPa of grouting pressure, grouting pressure step up, and reach pressure stabilizing after final grouting pressure 10min, slip casting pumpage should be controlled in 10~100L/min, grouting parameter and pressure for reference before testing, practical grouting parameter It is determined according to after field test slip casting effect.

4., grouting and reinforcing should be carried out continuously, when interrupting for some reason, break time should be less than the presetting period of slurries.

5., after ground reinforces, it is right after 28d (cement slurry) to terminate in grouting and reinforcing body intensity up to 75% or slip casting Reinforcing body carries out quality inspection, it is proposed that pass through test using mark and test, slip casting check point should not less than slip casting hole count 1% and No less than 3 points.Check point should be arranged in representational hole location, abnormal position (such as discontinuous reinforcing portion occurs in construction Position).

6., reinforce after soil layer mark pass through and answer >=30, if design requirement is not achieved, should make up in time.

7., grouting and reinforcing planar range be tunnel outer edge line extend out 2m；Vertical range is the above 5m in section threaded list road top The soil body to fill stratum bottom range.Plane effective reinforced area is about 10.4m, and vertical effective reinforced area is about 1.5~ 13.5m。

8., geological condition should be verified before construction, if management and designing unit should be notified in time by not being inconsistent with design drawing, with Just reinforcement form and range are adjusted.

9., monitoring measurement work must be reinforced critical process in work progress, find the problem to be handled in time, it is ensured that its The normal use and construction safety of buildings or structures, underground utilities within the scope of construction infection.

10., go out the section line ridge reinforcing scope Gao Po roadside have the new discovery landfill building waste higher than road periphery landform, infuse Slurry should be cleared grouting and reinforcing again to the new landfill building waste higher than the ridge Gao Po road in the reinforcing scope before reinforcing.

Specific range of grouting is as shown in Fig. 3, Fig. 4 and Fig. 5:

2) enter a section line grouting and reinforcing

According to grouting test as a result, the steel floral tube retrusive slip casting of proposed adoption ground to the stratum of Tunnel Passing carry out it is compacted and Filling and injecting slurry, slip casting pitch of holes 2m × 2m, front two rows are staggeredly arranged, and drill pipe laying depth 18.5m~27m.Isolation pile cutoff adds Gu range is tunnel two sides 0.5m (to isolation pile side), 9m on vault, 2m under inverted arch.Isolation pile external reinforcement range is tunnel two sides 3m, 9m on vault, 2m under inverted arch.This running tunnel is mainly to the fill stratum for passing through range and tunnel top, mud coal layer, sandstone layer into Row pre grouting from the surface is reinforced, and Grouting Pipe usesThe steel pipe of wall thickness t=3.5mm.Grouting Pipe should be goed deep into reinforcing soil layer or less 0.5m.Reinforcing scope is reinforced using cement slurry, and slip casting tube spacing is longitudinal direction 1.5m, and horizontal spacing 1.45m (is staggeredly arranged).It reinforces Soil layer mark, which passes through, afterwards answers >=70, if design requirement is not achieved, should make up in time.Lateral effective reinforced area is about 14.3m, is vertically had Imitating reinforcing scope is about 13.5~19.2m.

It enters and leaves section slip casting and arranges table

It completes quasi- tunneling surface grouting within 15 days before tunnel excavation to reinforce, excavates and set horizontal inspecting hole inspection note in preceding hole Effect is starched, to the undesirable position of local slip casting effect, is reinforced using advanced tubule supplement grouting mode in hole.Reach pre- After determining effect (country rock closely knit, without infiltration), using the construction of three step benching tunnelling methods or CRD method, interim mesospore and interim inverted arch are reserved Condition of contact restores interim mesospore and interim inverted arch according to situation is monitored in hole when necessary, to accelerate construction progress, in hundred Buddhists Turn back line tunnel is completed before arrival just to prop up, i.e., " tunneling after first shield ", " shield after first tunneling " Shi Yinfa tunneling is avoided to apply Work security risk and shield cavitation quality risk.Note: just branch cavitation progress is 20 meters/month to CRD method, and three step benching tunnelling methods are 40m/ Month.

The analysis of 6.4 implementation results

The tunneling of section line entered on October 27th, 2015 out overlaps section, and November 22 is by overlapping section, hundred Buddhist section shields Entered a section line tunneling face on August 21st, 2015 influences section parallel, and pass through within August 29th influences section parallel, according to monitoring Metric data shows that ground settlement is up to 23mm, and bored tunnel clearance convergence is up to 17.2mm, and Vault settlement is up to 37.7mm, duct pieces of shield tunnel convergence are up to 5.2mm, and grand sink in section of jurisdiction is up to 5.5mm, codes and standards is all satisfied, to monitoring Data are analyzed, and different section difference operating condition bottom offset situation of change and its change mechanism are obtained；It demonstrates and overlaps parallel Section proximity Construction Technology correctness therefore, by a series of technologies and management measure, shield tunnel and shallow buried covered excavation Method tunnel overlaps Duan Jun and ensure that structure and construction safety quality parallel.

3.6.5. summarize and

Entering section line and main track left tunnel line (right line) structure minimum level spacing is 2.296m, enters section line and right line tunnel knot The minimum vertical spacing of structure is 2.124m；Enter a section line (with the parallel section of turn back line) leading mining method construction, first branch has been constructed, and (concrete reaches Design strength) after, main track section shield is just constructed the parallel section tunnel, first right line construction after left line；Before and after overlapping section up and down 20m range section after main track shield is first constructed, enters a section line section and just continues construction to overlap section, main track pays attention to reinforcing into section when constructing Line just props up horizontal and vertical deformation monitoring；Overlap before section enters the construction of section line, need to lower section constructed set up in main track tunnel it is interim Bracing members, preloading ballast in tunnel are removed after the completion of entering a section line and overlapping the lining construction of section two, and pay attention to reinforcing the water in main track tunnel Gentle vertical deformation and settlement monitoring；Mining method construction, which overlaps section, need to do advance geologic inspecting hole (depth is not less than 6m), work as inspecting hole Pre-grouting in hole is taken to reinforce in excavation construction when wall rock condition is poor.Wherein, enter section line mileage RDK0+169.550 extremely Single reinforced concrete isolation pile is set between RDK0+232.000 sections and main track (left and right line), and isolation pile should just be propped up prior to Tunneling by mining method Construction.Turn back line segment, shield by when reinforce monitoring tunnel at the beginning of the horizontal and vertical deformation of branch, when deformation is with shield driving When being gradually increased, it need to take in time and set up horizontal steel tube support in hole, control tunnel horizontal deformation.

Section line and main track left tunnel line (right line) structure minimum level spacing are 3.373m (2.916m), out section line and the right side out The minimum vertical spacing of line tunnel structure is 2.134m；The leading mining method construction of section line close tunnel section out, first branch have been constructed (concrete Reach design strength) after, main track section shield just starts to construct；The 20m range section before and after overlapping section up and down, main track are first constructed Afterwards, section line section just continues construction and overlaps section out, and main track pays attention to reinforcing the monitoring of section line out when constructing；It overlaps section and goes out the construction of section line Before, temporary steel support is set up in the main track tunnel that need to construct to lower section, preloading ballast in tunnel, section line to be gone out overlaps the lining of section two and applies It is removed after the completion of work, and pays attention to reinforcing the monitoring of main track；Mining method construction overlaps section and need to do advance geologic inspecting hole (depth is not less than 6m), pre-grouting in hole is taken to reinforce in excavation construction when inspecting hole wall rock condition is poor.

According to the special geological condition in In Nanning Area and existing overall arrangement and method for construction, applied to the Mining Method tunneling of section line is entered and left Work takes the ancillary measures such as precipitation, stratum grouting and reinforcing, isolation pile, in order to weaken underground water to banket, silt clay, flood The reduction of product/slide rock clay, reducing, there is the breathing of expansile mud stone to destroy, and prevents rich water sandstone from destroying water burst, uses Ground precipitation and structurally waterproof measure；In order to such as banket to weak soil, silt clay, proluvial/slide rock clay carry out pre-reinforcement, Using surface grouting measure；In order to lower main track and enter and leave influencing each other for section line parallel section, uses isolation pile and carry out The main track of partial sector is separated with section line is entered and left；In order to increase the excavation stability in weak surrounding rock, pipe shed method pair is used Partial sector has carried out pre support.It has effectively ensured and has overlapped going on smoothly for section construction parallel.

The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.

Claims (10)

1. earth pressure balanced shield, EPBS is parallel with shallow burial hidden digging tunnel to overlap construction method, which is characterized in that including dewatering design and Construction, big cross section Mined, light section shallow buried covered excavation rapid construction technology, the parallel section control technology of shield-tunneling construction and shield Structure construction overlaps a section control technology.

2. earth pressure balanced shield, EPBS according to claim 1 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: the dewatering design and construction as follows include core pipe production prepare, drilling machine march into the arena, location and installation, aperture, lower mouth guard tube, Punching changes slurry, downhole pipe, dilutes mud, fills out filtrate, sealing sealing of hole, well-flushing, lower pump examination pumping, reasonable arrangement row behind drilling, whole hole Water lines and cable circuit, formally draw water and record test；

Described to fill out filtrate: mud is diluted to 1.05 or so afterwards in place by well casing, and when diluting mud, well casing nozzle should be sealed, and makes mud Slurry gradually should be carried out slowly from ground, dilution mud is returned between ring-type of the filter through well casing and hole wall.Dilution mud balance exists Pump amount is turned down after 1.05, filling 10~20mm gravel packing is at away from aperture 2m.When filling out filtrate, well head is first covered, using people Work is uniformly slowly inserted from well casing surrounding, meanwhile, using water filling filler, slow filler.

3. earth pressure balanced shield, EPBS according to claim 1 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: big cross section Mined is as follows: using three benching tunnelling methods, step uses short step, and upper half section preliminary bracing includes: Advanced tubule, first pneumatically placed concrete install anchor pole, hang steel mesh, vertical grid steel frame, pneumatically placed concrete to design thickness；

When wall rock geology is poor, excavated surface is unstable, using short drilling depth or up/down steps be staggered excavation or reserved core Native measure reinforces excavated surface using gunite concrete or glass fibre anchor pole；

Isolation pile is arranged in the range of shield section and bored tunnel clear distance less than 4m.

4. earth pressure balanced shield, EPBS according to claim 1 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: light section shallow buried covered excavation rapid construction technology includes benching tunnelling method excavation and earth excavation；

Benching tunnelling method includes top bar excavation and support, get out of a predicament or an embarrassing situation excavation and support and inverted arch excavation and support；

Top bar excavation and support sequence of construction: temporary enclosed face (depending on country rock situation), advanced tubule are squeezed into, are advanced small Conduit Grouting Consolidation, stay Core Soil excavate the top bar earthwork, measurement excavated section profile, just spray concrete 40mm, installation steelframe, It sets lock foot anchor tube, the longitudinally connected muscle of installation, hang steel mesh, again spray concrete to design thickness；

Get out of a predicament or an embarrassing situation excavation and support sequence of construction: left side abutment wall earth excavation, measurement excavated section profile, just spray 40mm thickness concrete, Installation steelframe sets anchor pole, hangs steel mesh, again spray concrete to design thickness, right side abutment wall earth excavation, measurement excavated section wheel Wide, first spray 40mm thickness concrete installs steelframe, sets anchor pole, hangs steel mesh, again spray concrete to design thickness；

Inverted arch excavation and support sequence of construction: tunnel bottom earth excavation, measurement excavated section profile, just spray concrete 40mm, installation fashioned iron Arch hangs steel mesh, sprays concrete again to design thickness, and excavation length of inverted arch is not greater than 3m, digs to design profile, immediately Steelframe, injection coagulation are installed.

5. earth pressure balanced shield, EPBS according to claim 1 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: the parallel section control technology of shield-tunneling construction is as follows: apply isolation pile between bored tunnel and shield section, bored tunnel with When the clear distance in shield section is less than 4m, isolation pile is set between two works, the position selection of two face bouts exists Pile cutoff is isolated, shield, which could tunnel, to be passed through, and bored tunnel stops after excavating, and spray anchor closes face, is arranged in top bar bottom Fashioned iron stull, the perpendicular support of stull middle position setting, stull and perpendicular tie distance are identical with steel arch-shelf, and steel arch-shelf welding, stull it Between gunite concrete, make top bar closing cyclization, get out of a predicament or an embarrassing situation and inverted arch should excavate same position, and just branch closing cyclization.

6. earth pressure balanced shield, EPBS according to claim 1 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: it is as follows that shield-tunneling construction overlaps section control technology:, engineering dewatering processing good including quarrel land reform and injecting treatment.

7. earth pressure balanced shield, EPBS according to claim 6 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: quarrel land reform is good as follows: in clay stratum in driving, injecting foam to cutterhead face, Tu Cang and screw conveyor respectively；It is rich When water location and other aquifer water-bearing stratums tunnel, bentonite is injected into cutterhead face, native storehouse and in screw conveyor, and increase to spiral shell It revolves and injects bentonite in conveyer；When sandstone layer stratum is tunneled, mud is injected into cutterhead face, native storehouse.

8. earth pressure balanced shield, EPBS according to claim 6 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: engineering dewatering processing is as follows: area is arranged away from bored tunnel edge 2.3-2.5m, in turn back line isolation pile in dewatering well center Domain, dewatering well are set on the outside of two isolation piles between stake, and along tunnel longitudinal direction, two rows are staggeredly arranged.

9. earth pressure balanced shield, EPBS according to claim 6 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: injecting treatment includes section line grouting and reinforcing: running tunnel passes through in range and the fill stratum of tunnel top, to above-mentioned soil Layer carries out ground steel floral tube tunneling boring pre-pouring grout and reinforces；The test of craftsmanship injecting grout through steel perforated pipe is carried out before construction, to examine stratum to infuse The applicability of sizing process, and large area carries out mortar depositing construction after test effect reaches design requirement.

10. earth pressure balanced shield, EPBS according to claim 6 is parallel with shallow burial hidden digging tunnel to overlap construction method, feature Be: injecting treatment includes into a section line grouting and reinforcing: being carried out using stratum of the ground steel floral tube retrusive slip casting to Tunnel Passing Compacted and filling and injecting slurry, slip casting pitch of holes 2m × 2m, front two rows are staggeredly arranged.